Achieving High Quality Factor Interband Nanoplasmonics in the Deep Ultraviolet Spectrum via Mode Hybridization

Area of Science:

• Plasmonics and Nanophotonics
• Materials Science
• Deep Ultraviolet (DUV) Optics

Background:

• Interband plasmons (IBPs) in semiconductors offer plasmonic properties in the deep ultraviolet (DUV) spectrum due to negative permittivity from interband electronic transitions.
• Practical applications of IBPs are hindered by their broad resonance characteristics.

Purpose of the Study:

• To overcome the limitation of broad resonances in IBPs.
• To enhance DUV absorption and explore potential applications in UV blocking.

Main Methods:

• Hybridization of localized plasmon resonance in silicon nanostructures with Fabry-Pérot resonance in a SiO₂ dielectric layer on a silicon substrate.
• Simulation and experimental measurement of the quality factor (Q-factor) of the hybridized system in the DUV region.
• Integration of the hybridized DUV cavity with lignin-modified polyethylene glycol films to assess DUV absorption enhancement.

Main Results:

• Achieved a simulated Q-factor of approximately 43 and an experimentally measured Q-factor of 37 at ~4.6 eV in the DUV region.
• Demonstrated a 5.4-fold enhancement in DUV absorption for modified polyethylene glycol films using the hybridized DUV cavity.
• Validated the potential of the designed system for effective UV blocking applications.

Conclusions:

• The hybridization strategy effectively enhances the Q-factor of IBPs in the DUV spectrum.
• The developed platform shows significant promise for improving DUV absorption in functional materials.
• This versatile approach can be extended to other IBP systems, opening new avenues for UV-specific technologies.